On Mon, 22 Mar 2010 08:41:03 -0400, blueman wrote:

mm writes:
On Mon, 22 Mar 2010 00:00:28 -0400, aemeijers
wrote:
Oh yeah, I forgot to say something about that. Probably because I
haven't needed to do that for a long time. I think those red and
green felt washers must be responsible. I haven't had much in the way
of dirty batteries since I started using those.

- What are those "red and green felt washers"?
- Are they some after-market product that I can buy?

Yes, they used to be a dollar a pair. Maybe a little more now. I'm
sure they have them at "real" autoparts stores but they have them on
display usually at consumer autoparts stores like Pepboys.

I know some people don't think they work, but my personal impression
is that they work great. There have been some battery changes that
might possibly have made battery problems get less frequent but I'm
pretty sure I bougth the washers when I didn't change my battery and
there was a big improvement with the same battery. Put the red on
positive and the green on negative. I use the same washers for
years. It *is* a little hard to believe they don't wear out, use up
their chemicals, but who knows. All I know is I don't have gunk
problems anymore, and only use baking soda once every year or two or
three.

- Also, what causes this accumulation of gunk?
- Where does the "gunk" come from?

The liquid in the battery is sulfuric acid with a little lead
dissolved in it. The gunk is some sort of sulfate, with maybe, I
don't know for sure, some lead sulfate. That's why it's yellow, from
the sulfur.

- Does it mean the battery is leaking?

No. It does mean some acid got out, but that's not the same thing.

- Does it cause permanent damage to the battery?

No. There's loads of acid still left inside. It doesnt' take much
acid to make that crud.

- Does it mean the battery is nearing the end of its lifespan?

No. It's not like a flashlight battery's leaking.

About 20 or 30 years ago they came out with No-maintenance batteries,
which couldn't be opened to add water, and which also I think meant
that the acid coudn't get out. I lost track of whether these things
were as good as they said. Ialso lost track of whether there was
some small vent for each of the 6 cells in a 12 volt battery. I think
there was. I think they used a slightly different acid or plate
chemistry.

A couple years after that, they came out with Lo-maintenance
batteries, that looked like No-maintenance, in that there seemed to be
no caps for the cells, that the battery coudln't be opened to add
water. But they had just redesigned the caps, put 3 caps together
(and used two of them, for a total of 6 caps) with a very low profile
and no apparent place to lift, so they looked like No-maintence, and I
think the chemistry was slightly different so it was not necessary to
add distilled water as often as it used to be. And maybe voltage
regulation of the charging system had gotten better, because charging
with too high a voltage causes water to evaporate from the electroyte,
which is water and acid. Anyhow, it's true, I think, that one
doesn't have to add water to batteries nearly as often as one used to.
I'm not the best example of maintenance, but I only check the battery
ever couple years. I never needs much water, if any.

- Other than "red and green felt washers" is there anything I can do to
prevent such build-up in the future?

Be sure to tighten the terminals tight enough, but not too tight!!

I haven't looked for stainless steel bolts, and I did once in 45 years
have the bolt rust through, largely because of the battery acid, but
they sell replacement terminal bolts, and it was easy to replace it.

But once or more I havent' tightened the bolt enough. When it is at
all loose, that makes it more likely the crud on the outside will get
up between the post and the terminal. When it's properly tight, it
either doesn't or it takes longer, not positive. So one time, I'm
driving and the car stalled and I was taking a friend to catch a train
so I didn't want to waste time. I touched both terminals and one was
hot. That's because it was loose. I just turned it left and right as
much as it went and then tightened the bolt and the car was fine after
that. It wasn't actually that loose, and there was none of the
visible crud, but maybe there was something else.


Thanks for ALL the helpful replies...